1. Lab 3: Single-row Functions
CISB224 02A, 02B
Semester I, 2009/2010
College of Information Technology, Universiti Tenaga Nasional

2. LOWER() and UPPER()
Syntax
LOWER(character_expression)
UPPER(character_expression)
Returns a character expression, in lower-case or upper-case
The argument may be a:
Table column
String
Concatenation/combination of the above
College of Information Technology, Universiti Tenaga Nasional

3. LOWER() and UPPER() – cont.
Example 1
Display employees’ names and job titles. Display
the names in this format ‘LASTNAME, FirstName’
and give the column a suitable heading.
SELECT UPPER(LastName) + ‘, ‘ + FirstName AS Name, Title AS ‘Job Title’
FROM Employees
College of Information Technology, Universiti Tenaga Nasional

4. ROUND()
Syntax
ROUND(numeric_expression, length)
Returns a numeric expression, rounded to the specified length or precision
Accepts two arguments:
numeric_expression - value to be rounded up
length - precision to which the first argument is to be rounded, must be an integer
College of Information Technology, Universiti Tenaga Nasional

5. ROUND() – cont. Rounding up the value 457.923 to varying precisions:
Result -2
Round( , -2)  -1
Round( , -1) 
Round( , 0)  1
Round( , 1)  2
Round( , 2) 
College of Information Technology, Universiti Tenaga Nasional

6. ROUND() – cont. Example 2 Round up 457.923 to the hundreds. Example 3
SELECT ROUND( , -2)
Example 3
Round up to the hundredths, or to two
decimal places.
SELECT ROUND( , 2)
College of Information Technology, Universiti Tenaga Nasional

7. GETDATE() Returns the current system date and time Accepts no argument
Syntax
GETDATE()
Returns the current system date and time
Accepts no argument
College of Information Technology, Universiti Tenaga Nasional

8. DATEADD()
Syntax
DATEADD(date_part, numeric_expression, date_expression)
Returns a datetime value, the result of adding a specified length of time to a specified start date
Accepts three arguments:
date_part – Measure of time to add e.g. Day, Month, Year
numeric_expression – Multiple of the measure, to get a length of time e.g. 6 6 months
date_expression – Start date
College of Information Technology, Universiti Tenaga Nasional

9. DATEADD() – cont. Example 4 What date is 6 months from today?
SELECT GetDate() AS Today, DateAdd(Month, 6, GetDate()) AS ‘6 Months from Today’
Functions can be nested!
Here, GetDATE() is nested inside DateADD()
and used as the start date argument.
College of Information Technology, Universiti Tenaga Nasional

10. DATEDIFF()
Syntax
DATEDIFF(date_part, date_expression, date_expression)
Returns the length of time between two dates, in a specified measure of time
Accepts three arguments:
date_part – Measure of time to use e.g. Week, Day
date_expression – Start date
date_expression – End date
College of Information Technology, Universiti Tenaga Nasional

11. DateDiff() – cont. Example 5 How many days more to the National Day?
SELECT DateDiff(Day, ‘30 July, 2009’, ’31 August, 2009’)
Date string values are also
enclosed in single quotes!
College of Information Technology, Universiti Tenaga Nasional

12. DATENAME()
Syntax
DATENAME(date_part, date_expression)
Returns a character string representing the specified date part of the specified date
Accepts two arguments:
date_part – Part of the date to be returned
date_expression – Date to be used
College of Information Technology, Universiti Tenaga Nasional

13. DateName() – cont. Example 6 What month is it now?
SELECT DateName(Month, ‘8 August, 2007’)
Some other ways of writing date constants are:
'April 15, 1998'
'980415'
'04/15/98‘
Look up ‘Constants’ in Transact-SQL Help.
College of Information Technology, Universiti Tenaga Nasional

14. Convert() Converts an expression from one data type to another
Syntax
Convert(data_type[(length)], expression[, style])
Converts an expression from one data type to another
Accepts three arguments
data_type – data type to convert into
expression – expression to be converted
style – format of the returned expression (refer to the Transact-SQL Help)
College of Information Technology, Universiti Tenaga Nasional

15. Convert() – cont. Example 7
Display the employees’ start dates in British format
i.e. dd/mm/yy.
SELECT Name, Convert(char, StartDate, 3) AS ‘Hire Date’
FROM emp
College of Information Technology, Universiti Tenaga Nasional

16. Group Functions Function Description MAX(DISTINCT | ALL | expr)
Maximum value.
MIN(DISTINCT | ALL | expr)
Minimum value.
AVG(ALL | n)
Average value of n, ignoring null values.
SUM(DISTINCT | ALL | n)
Sum values of n, ignoring null values.
COUNT(*)
Returns the number of rows affected.
COUNT(DISTINCT | ALL | expr)
Returns the number of rows affected by expr.
College of Information Technology, Universiti Tenaga Nasional

17. MAX and MIN
Example 8
Display the minimum and maximum salary earn by the employee.
SELECT MIN(salary), MAX(salary)
FROM Emp
College of Information Technology, Universiti Tenaga Nasional

18. COUNT Example 9 Display the number of employees in Sales department
SELECT COUNT(*)
FROM emp
WHERE dept = ‘sales’
College of Information Technology, Universiti Tenaga Nasional

19. Group Functions
Syntax SELECT select_list FROM table_source [WHERE search_condition] [GROUP BY group_by_expression] [HAVING group_condition] [ORDER BY order_by_expression]
group_by_expression:
Specifies columns whose values determine the grouping rows
group_condition:
Restricts the groups of rows returned
College of Information Technology, Universiti Tenaga Nasional

20. Group Functions-cont. Example 1
Display the number of employee for each department. Name the column as ‘No of employee’
SELECT Dept, COUNT(*) ‘No of employee’
FROM Emp
GROUP BY Dept
College of Information Technology, Universiti Tenaga Nasional

21. WHERE or HAVING?
SELECT Dept, AVG(salary) FROM Emp WHERE AVG(salary) > 1500 GROUP BY Dept
SELECT Dept, AVG(salary)
FROM Emp
GROUP BY Dept
HAVING AVG(salary) > 1500
College of Information Technology, Universiti Tenaga Nasional